From b80d6defb7b018250ef4fafccff7c980aed6a444 Mon Sep 17 00:00:00 2001 From: Sebastien Buisson Date: Fri, 9 Jun 2023 14:50:25 +0200 Subject: [PATCH] LU-16888 gss: fix ptlrpc_gss automatic loading ptlrpc_gss kernel module is automatically loaded when a GSS security flavor is enforced. Loading success is recorded in a static variable in the ptlrpc module, which prevents further reloading in case ptlrpc_gss is unloaded while keeping ptlrpc loaded. Get rid of this static variable as it is not required in order to avoid calling request_module("ptlrpc_gss") when not needed. Indeed, once loaded, the static array policies[] has an entry at the SPTLRPC_POLICY_GSS index, indicating that the ptlrpc_gss module is loaded. Signed-off-by: Sebastien Buisson Change-Id: I9bb100a202fe9c3fc455a2ffba6ee6398e19b9bf Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/51264 Tested-by: jenkins Tested-by: Maloo Reviewed-by: Aurelien Degremont Reviewed-by: Andreas Dilger Reviewed-by: Oleg Drokin --- lustre/ptlrpc/sec.c | 34 +++++++++++++++++----------------- 1 file changed, 17 insertions(+), 17 deletions(-) diff --git a/lustre/ptlrpc/sec.c b/lustre/ptlrpc/sec.c index 7f616c9..38dc598 100644 --- a/lustre/ptlrpc/sec.c +++ b/lustre/ptlrpc/sec.c @@ -114,10 +114,9 @@ static struct ptlrpc_sec_policy *sptlrpc_wireflavor2policy(__u32 flavor) { static DEFINE_MUTEX(load_mutex); - static atomic_t loaded = ATOMIC_INIT(0); struct ptlrpc_sec_policy *policy; - __u16 number = SPTLRPC_FLVR_POLICY(flavor); - __u16 flag = 0; + __u16 number = SPTLRPC_FLVR_POLICY(flavor); + int rc; if (number >= SPTLRPC_POLICY_MAX) return NULL; @@ -127,25 +126,26 @@ struct ptlrpc_sec_policy *sptlrpc_wireflavor2policy(__u32 flavor) policy = policies[number]; if (policy && !try_module_get(policy->sp_owner)) policy = NULL; - if (policy == NULL) - flag = atomic_read(&loaded); read_unlock(&policy_lock); - if (policy != NULL || flag != 0 || - number != SPTLRPC_POLICY_GSS) + if (policy != NULL || number != SPTLRPC_POLICY_GSS) break; - /* try to load gss module, once */ + /* try to load gss module, happens only if policy at index + * SPTLRPC_POLICY_GSS is not already referenced in + * global array policies[] + */ mutex_lock(&load_mutex); - if (atomic_read(&loaded) == 0) { - if (request_module("ptlrpc_gss") == 0) - CDEBUG(D_SEC, - "module ptlrpc_gss loaded on demand\n"); - else - CERROR("Unable to load module ptlrpc_gss\n"); - - atomic_set(&loaded, 1); - } + /* The fact that request_module() returns 0 does not guarantee + * the module has done its job. So we must check that the + * requested policy is now available. This is done by checking + * again for policies[number] in the loop. + */ + rc = request_module("ptlrpc_gss"); + if (rc == 0) + CDEBUG(D_SEC, "module ptlrpc_gss loaded on demand\n"); + else + CERROR("Unable to load module ptlrpc_gss: rc %d\n", rc); mutex_unlock(&load_mutex); } -- 1.8.3.1